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