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)(19,27)(20,29)(23,32)(24,28) involution — undirected(2,5)(3,7)(9,11,12,15)(10,13,14,16)(17,18)(19,28)(20,23)(21,25)(22,31)(24,27)(26,30)(29,32)(10,14)(13,16)(17,19,22,20,21,27,30,29)(18,23,26,28,25,32,31,24)(2,5)(6,8)(19,27)(20,29)(23,32)(24,28) involution — undirected(1,3,4,7)(2,6,5,8)(17,20,22,27,21,29,30,19)(18,24,26,23,25,28,31,32)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.