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