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