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