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