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