Option 1: Use commas to separate the appositives.
* Leonardo da Vinci, inventor, painter, and poet, is considered a true genius.
Option 2: Use dashes to set off the appositives.
* Leonardo da Vinci—inventor, painter, and poet—is considered a true genius.
Option 3: Use parentheses to set off the appositives.
* Leonardo da Vinci (inventor, painter, and poet) is considered a true genius.
Option 4: Use colons to introduce the appositives.
* Leonardo da Vinci is considered a true genius: inventor, painter, and poet.
All of these options are grammatically correct. The best choice will depend on the desired emphasis and tone of the sentence.