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