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