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