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