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