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