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