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