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