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