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