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