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