Using a food processor, puree the cantaloupe until smooth. Strain through a strainer; discard the solids.
Fill six 12- to 14-oz. collins or highball glasses with ice. Into each glass, slowly pour 1/2 oz. grenadine, 1 1/2 oz. cantaloupe juice, 1/2 oz. orange liqueur, 1 oz. limoncello and 1 oz. fresh lemon juice, letting each liquid settle to the bottom before pouring the next one to create layers.
Just before serving, fill each glass with club soda and stir. Garnish with a twist.