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