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