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