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