Cut ends off fruit. In 2-quart saucepan, mix sugar and water; add ends of fruit. Heat to boiling; boil 3 minutes. Cool; discard ends. Cut remaining limes, oranges and lemon into thin slices.
In 3-quart non-metal container, mix sugar-water mixture, grape juice and liqueur. Add fruit slices; refrigerate. Just before serving, add sparkling water; stir gently.