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