Yes, your All Star driver can be ANYONE in the race. It doesn't have to be someone that you picked in group 1, 2, 3, or 4 either.
For example, your roster for Daytona can be:
GROUP 1...Kevin Harvick
GROUP 2...Kyle Busch
GROUP 3...Paul Menard
GROUP 4...Jamie McMurray
ALL STAR...Dale Earnhardt, Jr.