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