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