I think they view themselves as savages, and are proud of it. Based on their subsequent behaviour, Jack's gang shed all moral restraint by the time they kill a mother pig. Given the way they communicate - "a littlun howled, creased and crimson"/"double cry"/"ululation"/"high, bird-like cry"/"silvery laughter" - they probably don't class their tribe as a cultured company. You only have to take one look at Jack's behaviour in chapter 3 to see how much shame he has in being wild:
Jack was bent double [...] his nose only a few inches from the humid earth. [...] Then dog-like, uncomfortable and on all fours yet un-heeding his discomfort, he stole forward five yards and stopped. [...] His sandy hair, considerably longer than it had been when they dropped in, was lighter now; and his bare back was a mass of dark freckles and peeling sunburn. A sharpened stick about five feet long trailed from his right hand; and except for a pair of tattered shorts held up by his knife-belt he was naked. [...] they were bright blue, eyes that in this frustration seemed bolting and nearly mad. [...] Jack himself shrank at this cry with a hiss of indrawn breath; and for a minute he became less of a hunter than a furtive thing, ape-like among the tangle of trees.
The advent of the masks is pivotal to advancing the plot. Originally, Roger throws stones but 'aims to miss' as a result of what Golding calls 'the taboo of old life'. But when he and Jack, and soon the rest of the tribe, can be camoflaged 'like moths on a tree trunk', I'm sure they have no problem identifying themselves as savages.
He looked in astonishment, no longer at himself but at an awesome stranger. [...] He began to dance and his laughter became a bloodthirsty snarling. He capered towards Bill, and the mask was a thing on its own, behind which Jack hid, liberated from shame and self-consciousness."
The language is deliberately enticing, as if Jack rejoices at his new personna. He doesn't 'jump' or 'leap', he 'capers'. I would go as far to say that his new barbaric appearance makes him euphoric. Certainly, Roger changes drastically once he learns his misdeeds will not bear any connection to a boy who was once kept in line by the threat of punishment, so he kills Piggy with no shame, and tortures Samneric without holding back; without aiming to miss. In this way, he becomes Jack's willing henchman, stopping at nothing to do his dirty business for him. Are these the actions of a boy who would class himself as savage? Absolutely.
I see no reason to assume that Jack's tribe would have any reason not to class themselves as savages. Jack even advertises the primitive activities of his tribe to the whole island population:
"Listen all of you. Me and my hunters, we're living along the beach by a flat rock. We hunt and feast and have fun."
He speaks under no pretence of sophistication, which suggests he is not ashamed of what they do. Compare his non-standard use of 'me and my hunters' to his upper-class language when he is first summoned by 'the sound of the shell':
"All right then. Sit down. Let him alone. [...] He's always throwing a faint. / He did in Gib.; and Addis; and at matins over the precentor. [...] All right choir. Take off your togs. [...] I should think this is the easiest way. [...] We're English; and the English are best at everything."
Of course, there's the everlasting
Kill the beast! Cut his throat! Spill his blood!
And don't forget their twisted sense of humour that lacks any sense of self-reproach after they have butchered the pig:
"Right up her ass!"
"Did you hear?"
"Did you hear what he said?"
"Right up her ass!"
Not to mention the fact that none of the tribe bother to counter Piggy's insulting points:
"I've got this to say. You're acting like a crowd of kids. Which is better - to be a pack of painted [******] like you are, or to be sensible like Ralph is? Which is better - to have rules and agree, or to hunt and kill? Which is better, law and rescue, or hunting and breaking things up?
Probably, the lack of reaction from the tribe means that none of them oppose Piggy's claims that they are 'kids', or less than sensible. Considering how everyone hates Piggy (which is something they get from Jack), the fact that they let Piggy's arguments lie could well mean that they themselves view themselves as savages. At the very least, it demonstrates an inability to reason that would result from accepting their lives as being savage.
Note how none of them reject Jack's savage orders -
"Go on. Tie them." / "See? they do what I want."
The act of tying innocent people up is so stereotypically savage, and the fact that 'they felled the twins clumsily and excitedly', hints that they see themselves as savages.
And when Jack superstitiously announces "This head is for the beast. It's a gift", the reader is left in no doubt of his savageness, and I don't think the tribe is either.