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