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