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