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