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