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)(25,26,30,34)(27,31,32,28)(29,37,39,33)(35,36,40,38)(6,8)(11,17)(15,20)(18,23)(22,24)(25,27,30,32)(26,28,34,31)(29,35,39,40)(33,36,37,38)(5,6)(7,8)(9,10,13,14)(11,15,17,20)(12,16,19,21)(18,22,23,24)(25,27)(26,31)(28,34)(29,35)(30,32)(33,38)(36,37)(39,40)(1,2)(3,4)(9,11)(10,15)(12,18)(13,17)(14,20)(16,22)(19,23)(21,24)(25,28,30,31)(26,32,34,27)(29,38,39,36)(33,35,37,40)(9,12)(10,16)(11,18)(13,19)(14,21)(15,22)(17,23)(20,24)(25,29,30,39)(26,33,34,37)(27,35,32,40)(28,36,31,38)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.