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