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