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