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