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