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