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