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