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