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