Bring a large pot of salted water to a boil, add the shrimp, and poach for 2 to 3 minutes until pink and opaque.
Drain the shrimp immediately and transfer to an ice bath to stop the cooking process; chill for 5 minutes and then pat dry.
In a small bowl, whisk together the olive oil, lime juice, honey, salt, and pepper until the vinaigrette is emulsified.
In a large mixing bowl, combine the chilled shrimp, grapefruit segments, orange segments, and cubed avocado.
Add the chopped cilantro and drizzle the vinaigrette over the mixture, tossing gently to coat without mashing the avocado.
Divide the mixed greens among four plates and top with the citrus shrimp and avocado mixture.