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)(11,18)(12,16)(13,15)(14,19)(17,21)(20,22)(23,24)(25,26,31,36)(27,32,28,38)(29,34,30,35)(33,37,40,39)(2,5)(6,7)(9,11)(10,14)(12,19)(13,20)(15,23)(16,18)(17,22)(21,24)(25,27,29,39,31,28,30,37)(26,32,34,33,36,38,35,40)(10,15)(11,19)(13,21)(14,22)(16,17)(18,23)(25,28,31,27)(26,33,36,40)(29,39,30,37)(32,35,38,34)(1,3,4,8)(2,6,5,7)(10,16)(14,18)(15,17)(22,23)(25,29,31,30)(26,34,36,35)(27,37,28,39)(32,40,38,33)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.