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