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