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