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