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