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