A group of men in blue shirts, banded hats, and red bandannas stand in a group.
a bunch of guys in colorful clothes stand together
The guys stand together because they stand in a group.
A "bunch of guys: is a restatement of "a group of men".  Colorful clothes is a restatement of "blue shirts, banded hats, and red bandannas."  "Together" is a different word for "group"
A bunch of guys is a group of men.  Blue shirts and red bandannas are colorful clothes.  Men standing in a group stands together.