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