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