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