One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,8)(5,6)(9,10)(11,19)(12,23)(13,26)(14,18)(15,20)(16,25)(17,27)(21,35)(22,32)(24,38)(28,37)(29,34)(30,39)(31,33)(36,40) involution — undirected(2,6)(7,8)(11,20)(12,24)(13,27)(15,19)(17,26)(21,36)(22,34)(23,38)(28,31)(29,32)(33,37)(35,40) involution — undirected(1,3,5,4)(2,7,6,8)(9,11,13,20,14,22,27,34)(10,15,17,19,18,29,26,32)(12,21,25,33,24,37,39,36)(16,28,23,31,30,35,38,40)(1,4,5,3)(2,8,6,7)(9,12,13,25,14,24,27,39)(10,16,17,23,18,30,26,38)(11,21,20,33,22,37,34,36)(15,28,19,31,29,35,32,40)(2,6)(7,8)(11,22)(15,29)(19,32)(20,34)(21,37)(28,35)(31,40)(33,36) 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.