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