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