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