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