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