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