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