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