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