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