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