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