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)(11,16)(12,20)(13,18)(14,15)(17,22)(19,21)(23,24)(25,26)(27,30)(28,33)(29,32)(31,36)(34,38)(35,40)(37,39)(3,7)(5,8)(10,15)(11,19)(17,20)(18,24)(25,26)(27,30)(28,31)(29,32)(33,36)(34,38)(35,39)(37,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(10,15)(11,19)(17,20)(18,24)(26,27)(31,33)(32,34)(39,40) involution — undirected(1,3,4,7)(2,5,6,8)(9,11,14,19)(10,16,15,21)(12,18,22,24)(13,17,23,20)(25,27,30,26)(28,33,36,31)(29,32,38,34)(35,39,37,40)(1,2)(3,5)(4,6)(7,8)(9,12,14,22)(10,17,15,20)(11,18,19,24)(13,16,23,21)(25,28)(26,31)(27,33)(29,37)(30,36)(32,40)(34,39)(35,38)(9,13,14,23)(10,18,15,24)(11,20,19,17)(12,21,22,16)(25,29,30,38)(26,32,27,34)(28,35,36,37)(31,39,33,40)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.