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