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