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)(11,22)(12,26)(13,29)(14,20)(15,23)(16,21)(17,18)(19,33)(24,30)(25,28)(27,35)(31,37)(32,36)(34,39)(38,40) involution — undirected(2,5)(6,8)(9,11,16,26,14,18,15,25)(10,17,21,28,20,22,23,12)(13,24,33,40,31,35,32,39)(19,34,37,30,36,38,29,27)(1,3)(2,6)(4,7)(5,8)(9,12,15,17,14,28,16,22)(10,18,21,26,20,11,23,25)(13,30,32,38,31,27,33,34)(19,24,37,39,36,35,29,40)(3,7)(6,8)(9,13)(10,19)(11,24)(12,27)(14,31)(15,32)(16,33)(17,34)(18,35)(20,36)(21,37)(22,38)(23,29)(25,39)(26,40)(28,30) 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.