I would take another rest day or two if they are that sore. You could still go for shorter rides in the meantime say 5 mile or under if you just need to get out. Just don't be smashing the big gears and just spin on lower gears. Once your legs feel better then go for a 25 mile ride then take a day off. Rinse and repeat and you will feel each time you go out you will be stronger than the last time.