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