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