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