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