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