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