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