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