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