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