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)(25,26,31,28)(27,34,29,32)(30,36,38,33)(35,39,37,40)(1,3,4,7)(2,5,6,8)(9,11,15,12)(10,13,16,19)(14,18,23,20)(17,21,22,24)(25,27,31,29)(26,32,28,34)(30,35,38,37)(33,39,36,40)(1,2)(3,5)(4,6)(7,8)(10,16)(11,12)(14,23)(21,24)(26,28)(30,38)(32,34)(35,37) involution — undirected(9,12,15,11)(10,13,16,19)(14,20,23,18)(17,21,22,24)(25,28,31,26)(27,34,29,32)(30,36,38,33)(35,40,37,39)(1,3)(2,5)(4,7)(6,8)(9,13)(10,12)(11,16)(14,21)(15,19)(17,20)(18,22)(23,24)(25,29,31,27)(26,32,28,34)(30,37,38,35)(33,39,36,40)(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)(26,33)(27,35)(28,36)(29,37)(31,38)(32,39)(34,40) 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.