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