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