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