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)(11,16)(12,17)(13,15)(14,19)(18,26)(20,27)(21,30)(22,29)(23,28)(24,33)(25,32)(31,36)(34,37)(35,39)(38,40) involution — undirected(10,15)(11,20)(12,23)(13,26)(16,29)(17,32)(18,19)(21,24)(22,36)(25,37)(30,40)(33,39) involution — undirected(2,5)(6,8)(9,11,13,20,14,22,26,36)(10,16,15,27,19,29,18,31)(12,24,23,38,25,21,37,35)(17,33,28,40,32,30,34,39)(9,12,13,23,14,25,26,37)(10,17,15,28,19,32,18,34)(11,21,20,35,22,24,36,38)(16,30,27,39,29,33,31,40)(1,3,4,7)(2,6,5,8)(12,25)(17,32)(21,24)(23,37)(28,34)(30,33)(35,38)(39,40)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.