How can i discreetly let him know i "want him"?

my group of friends consist of 5 guys & 3 girls & we all get together every day almost.. so were always together.. well me & one of the guys have a ual past & im tryna bring it back.. no strings attacted.. if you know what i mean.. so what are some things i can do to flirt with him or turn him on.. even tho our other friends are around..