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