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