One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(17,18)(19,25)(20,28)(21,23)(22,27)(24,30)(26,32)(29,31) involution — undirected(9,10,13,16)(11,15,12,14)(17,19,21,26)(18,22,23,31)(20,29,30,27)(24,32,28,25)(2,5)(6,8)(9,11,13,12)(10,14,16,15)(19,26)(22,31)(25,32)(27,29)(9,12,13,11)(10,15,16,14)(19,26)(22,31)(25,32)(27,29)(1,3,4,7)(2,6,5,8)(18,23)(22,31)(24,28)(25,32)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.