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