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