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