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