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