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)(23,31)(24,27)(25,29)(26,30)(28,34)(32,35)(33,36) involution — undirected(1,2,3,4)(6,10)(11,19)(12,17)(13,20)(23,32)(28,36)(31,35)(33,34)(5,7,8,14)(6,11,10,19)(9,18,16,15)(12,20,17,13)(22,27)(24,25)(28,35)(29,30)(31,36)(33,34)(21,23,26,32)(22,28,30,36)(24,34,25,33)(27,35,29,31)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.