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