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