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