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