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