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