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