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