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