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