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