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