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)(13,16)(19,23)(21,24)(25,26)(27,33)(28,35)(29,32)(30,31)(34,38)(36,40)(37,39)(1,3,7,6)(2,8,5,4)(17,18,20,22)(19,21,23,24)(26,31)(28,33)(29,37)(34,40)(1,4)(2,6)(3,5)(7,8)(9,10,12,14)(11,13,15,16)(17,18)(19,21)(20,22)(23,24)(25,27,30,35)(26,28,31,33)(29,34,37,40)(32,36,39,38)(1,5,7,2)(3,8,6,4)(9,11,12,15)(10,13,14,16)(17,19)(18,21)(20,23)(22,24)(25,28)(26,27)(29,38)(30,33)(31,35)(32,40)(34,39)(36,37)(1,6,7,3)(2,8,5,4)(25,29)(26,32)(27,34)(28,36)(30,37)(31,39)(33,38)(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.