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