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