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