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