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