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