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