One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,5)(6,8)(11,12)(14,16) involution — undirected(2,5)(6,7)(9,10,13,15)(11,16,12,14)(17,18)(19,26)(20,23)(21,24)(22,28)(25,29)(27,31)(30,32)(9,11,13,12)(10,14,15,16)(17,19,21,28)(18,22,24,26)(20,27,29,32)(23,30,25,31)(9,12,13,11)(10,14,15,16)(18,23)(20,29)(22,30)(24,25)(26,31)(27,32)(1,3,4,8)(2,6,5,7)(18,24)(22,26)(23,25)(30,31)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.