In a pot, boil corn for 5 to 7 minutes, or until tender. Drain and set aside to cool.

In a bowl, whisk together oil, vinegar, parsley, basil, sugar, lemon juice, salt (if using), and cayenne.

Cut cooled corn off cob and add to oil mixture. Add tomatoes, onions, and peppers to corn and oil mixture. Stir to combine. Chill in the refrigerator for several hours or overnight.