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