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