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