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