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