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