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