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