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