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