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