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