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