One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,6)(7,8,12,16,13,17,11,25)(9,18,20,14,21,28,26,29)(10,15,24,31,22,30,23,35)(19,32,34,27,33,38,36,37)(7,9,12,20,13,21,11,26)(8,14,16,28,17,29,25,18)(10,19,24,34,22,33,23,36)(15,27,31,38,30,37,35,32)(4,6)(7,10)(8,15)(9,19)(11,23)(12,24)(13,22)(14,27)(16,31)(17,30)(18,32)(20,34)(21,33)(25,35)(26,36)(28,38)(29,37) involution — undirected(10,22)(15,30)(19,33)(23,24)(27,37)(31,35)(32,38)(34,36) involution — undirectedA 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.