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