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