The Ospreys starlet has been in scintillating form for the RaboDirect PRO12 champions in his debut season, notching five tries in 13 appearances - enough to catch the eye of interim coach Rob Howley ahead of Wales' defence of their crown.
And it is former Ospreys stalwart Williams - Wales' all-time leading try-scorer, with 60 tries in 91 international caps for the Red Dragons and the British Lions - whose example he is hoping to follow when he does make his first appearance.
"Shane's an outstanding player and a great friend as well. He's definitely someone to look up to," said Walker.
"I'd like to think I have learned a thing or two. He is any winger's hero in Wales and in world rugby.
"I was fortunate to have a few years training with him coming through the academy and then stepping up to the senior squad."
And the former Swansea man admits the meteoric rise in his debut season, from promising youngster to a member of the Wales senior side, has exceeded even his own wildest expectations.
"My goals at the beginning of the year were just to come back fit after the shoulder injury I had in pre-season and get the starting jersey for the Ospreys," he added.
"Confidence is growing with each game. I'm still learning and just enjoying my rugby.
"Ever since I picked up a ball it was a goal as a kid. It's a dream of any Welsh rugby player."