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