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