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)(11,19,22,15)(12,23)(13,17)(14,18)(16,25)(20,28,36,33)(21,34,38,29)(24,31)(26,30)(27,32)(35,39,37,40)(2,5)(3,8)(6,7)(9,11)(10,15)(12,20)(13,21)(14,22)(16,28)(17,29)(18,19)(23,33)(24,35)(25,36)(26,37)(27,38)(30,39)(31,40)(32,34) involution — undirected(2,6)(5,7)(9,12,14,25)(10,16,18,23)(11,20,22,36)(13,26,27,24)(15,28,19,33)(17,31,32,30)(21,37,38,35)(29,40,34,39)(9,13,14,27)(10,17,18,32)(11,21,22,38)(12,24,25,26)(15,29,19,34)(16,30,23,31)(20,35,36,37)(28,39,33,40)(10,18)(15,19)(16,23)(17,32)(28,33)(29,34)(30,31)(39,40) 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.