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