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