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