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