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