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