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