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