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