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)(14,15)(20,27)(24,31)(26,29)(28,32) involution — undirected(2,5)(6,7)(9,10,13,16)(11,15,12,14)(17,18)(19,23)(20,28)(21,30)(22,25)(24,29)(26,31)(27,32)(9,11,13,12)(10,14,16,15)(17,19,22,21)(18,23,25,30)(20,26,27,29)(24,28,31,32)(9,12,13,11)(10,15,16,14)(17,20,21,29,22,27,19,26)(18,24,23,28,25,31,30,32)(1,3,4,8)(2,6,5,7)(17,19,22,21)(18,23,25,30)(20,26,27,29)(24,28,31,32)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.