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