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