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