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