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