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