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