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