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