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