Grate the chayote and red cabbage, chop the fresh parsley and oregano, and halve the cherry tomatoes.
In a separate small bowl, make a simple vinaigrette with oil, vinegar, parsley, oregano, and salt and pepper to taste.
Put the farro and all the prepared veggies in a large bowl, and pour the vinaigrette on top. Mix until well combined, and taste for salt and pepper. Let the salad chill in the fridge until serving time.