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