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