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