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