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