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)(16,20)(18,19)(21,22,25,28)(23,26,29,32)(24,27,31,34)(30,33,35,36)(2,3)(5,7)(6,9)(8,11)(10,12)(13,14,17,15)(16,18,20,19)(23,29)(26,32)(30,35)(33,36)(2,3)(6,8)(7,12)(13,15,17,14)(16,19,20,18)(21,22)(23,26)(24,27)(25,28)(29,32)(30,33)(31,34)(35,36)(1,3,4,2)(5,8,10,6)(7,9,12,11)(13,16)(14,18)(15,19)(17,20)(21,23)(22,26)(24,30)(25,29)(27,33)(28,32)(31,35)(34,36)(5,9)(6,7)(8,12)(10,11)(21,24,25,31)(22,27,28,34)(23,30,29,35)(26,33,32,36)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.