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