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