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