I have only seen the film once, so until online transcripts start to appear, I can't really quote anything. The relevant bits I remember occurring when Scotty tries to open the hatch on the Vengeance
to receive Kirk and Khan, and the big guy comes to challenge him at the console: Scotty asks questions and, since the big guy isn't forthcoming with answers, introduces his own answers as well.
I might be completely off base there, though.
We saw another actual member in Enterprise. A former Starfleet Security officer named "Harris" had recruited Malcolm Reed to be a member of S31, and we saw Reed try to quit the organization.
Well, that's the ancient, pre-Federation organization that Sloan probably built his personal fantasy around - just like the secret societies of today that pretend to draw legitimacy from ancient origins. Anybody working for SF Intel would know about this old organization, and about half the agents would have wet dreams about reviving it. But whether those amounted to anything much in practice...