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