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