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