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