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