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