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