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