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