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