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