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