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