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