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