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