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