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