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