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