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