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