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