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