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