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