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)(11,15)(12,22)(13,17)(14,18)(16,19)(20,24)(21,23)(26,31)(28,32)(34,37)(36,39) involution — undirected(2,5)(6,7)(9,11,16,14)(10,15,19,18)(12,21,13,20)(17,24,22,23)(25,26)(27,32)(28,33)(29,34)(30,31)(35,39)(36,40)(37,38)(1,2)(3,6)(4,5)(7,8)(9,12,16,13)(10,17,19,22)(11,20,14,21)(15,23,18,24)(25,27,30,33)(26,32,31,28)(29,35,38,40)(34,39,37,36)(1,3)(2,6)(4,8)(5,7)(9,13,16,12)(10,17,19,22)(11,21,14,20)(15,23,18,24)(25,26)(27,32)(28,33)(29,37)(30,31)(34,38)(35,36)(39,40)(9,14,16,11)(10,18,19,15)(12,21,13,20)(17,24,22,23)(25,28,30,32)(26,33,31,27)(29,36,38,39)(34,40,37,35)(9,15,16,18)(10,11,19,14)(12,23,13,24)(17,20,22,21)(25,29,30,38)(26,34,31,37)(27,35,33,40)(28,36,32,39)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.