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