I'm going to go against the trend here, and say that in my opinion the grey does not make you look younger. But it doesn't make you look older either. To my mind it makes you look more REAL, in that it's obviously your own colour, and looking at your face, also obvious that you've gone grey relatively early.

The longer you dye your hair (not you specifically, you in general), the more of a mismatch there is between hair and face, which can be quite disconcerting.

You look terrific. You've encouraged me just that much more to quit dye completely