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