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