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