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