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