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