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