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