One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,13)(8,10)(9,17)(11,15)(12,16)(14,20)(18,19)(21,22)(23,27)(24,28)(25,29)(26,30)(31,36)(32,34)(33,35) involution — undirected(1,2,3,4)(6,10)(11,19)(12,17)(13,20)(21,23)(22,27)(24,32)(25,33)(26,31)(28,34)(29,35)(30,36)(5,7,8,14)(6,11,10,19)(9,18,16,15)(12,20,17,13)(22,28)(24,25)(27,34)(29,30)(32,33)(35,36)(22,29)(23,31)(24,25)(27,34)(28,30)(35,36) involution — undirectedA 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.