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