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