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