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