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