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