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