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