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