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