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