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