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