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