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