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