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