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