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