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