The Sentence Diagram Generator visually represents the sentence "Many people in the store were talking and laughing" as follows:

              +---------------------+
              |        were         |
              +---------------------+
               /                     \
        +-----------+             +-----------+
        |  talking  |             |  laughing  |
        +-----------+             +-----------+
               |
        +---------------------+
        |        Many         |
        +---------------------+
               |
        +-----------+
        |   people  |
        +-----------+
               |
        +---------------------+
        |        in           |
        +---------------------+
               |
        +-----------+
        |   store   |
        +-----------+

This diagram illustrates the subject "many people," the prepositional phrase "in the store," and the compound predicate "were talking and laughing."