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