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