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