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