Final answer:
The figure of speech used in the passage is an implied metaphor, drawing a comparison between John's social behavior and the movement of a bee or butterfly among flowers without stating it outright.
Step-by-step explanation:
The literary device used by the author in the passage is implied metaphor. An implied metaphor does not directly state that one thing is another, but instead suggests a comparison without using 'like' or 'as', which are characteristic of similes. In the given excerpt, John is described as 'flying from person to person, busily making friends with everyone,' suggesting a comparison to a bee or a butterfly without explicitly stating it. This is a comparison of John's social behavior to the way a bee or butterfly might move quickly from flower to flower.