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