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