Idiom: Social butterfly
Example
"Julia is the most outgoing person I know. She has friends on all of the sports teams, school activities committees and every other group at school! She is a true social butterfly."
Meaning: A social butterfly is a person - girl or boy - who is extroverted, enjoys meeting and talking to new people, and does not confine him/herself to only a few social groups. A social butterfly socializes with everyone.