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