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