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