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