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