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