I assume, you want to re-use the CB user profile data and avatar/image fields etc.
Unfortunately, the build-in userlist feature does not have a grid or blog layout. It is a table style, and it creates one row per user.
Maybe JoomlaXTC's
CB Avatar Wall
is an alternative. Its a module... but that should be no major problem. There ssems to be a fixed number of supported fields... not sure if this can be modified or extended... you may ask their support. I suggest a look into the Docs and parameters.
Demo Page1
Demo Page2
Docs
I remember, there was similar topic... please, do a search. Maybe there was another solution...