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