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