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