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)(17,18,21,20)(19,23,24,22)(25,26)(27,30)(28,31)(29,34)(32,38)(33,36)(35,40)(37,39)(2,5)(6,8)(17,18,21,20)(19,22,24,23)(26,27)(31,33)(32,34)(39,40)(1,2,4,5)(3,6,7,8)(9,11,12,16)(10,13,14,15)(17,19,21,24)(18,22,20,23)(25,27,30,26)(28,33,36,31)(29,34,38,32)(35,40,37,39)(9,10)(11,13)(12,14)(15,16)(17,20,21,18)(19,23,24,22)(25,28,30,36)(26,31,27,33)(29,37,38,35)(32,40,34,39)(1,3,4,7)(2,6,5,8)(25,29)(26,32)(27,34)(28,35)(30,38)(31,39)(33,40)(36,37)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.