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