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