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