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