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