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