nothing you do between now and saturday will actually give you any physiological benefit before the ride. i think it takes like 7-10 days for training - especially hard training - to take effect, so definitely don't do intervals/hill repeats/really hard rides. it'll only tire you out.

if you want to be as prepared as possible for saturday - basically race-ready - go easy friday. don't take it completely off; just spin easy for 30-60 minutes or something, maybe with a couple short accelerations (like 80%, not max) to loosen up your legs. tomorrow, just go for a normal training ride, 30ish miles or something. not too fast, don't push it too much on the hills...just steady state riding.

that's what i'd do, anyway.