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