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