The Sentence Diagram Generator visually represents the grammatical structure of the sentence: "We are going to have to stop halfway to charge and get snacks for the weekend at a Walmart."

1. Subject: We
2. Verb Phrase: are going to have to stop
   • Main Verb: stop
   • Infinitive Phrase: to charge and get snacks
     • Coordinating Conjunction: and
     • Noun Phrase: snacks
3. Adverbial Phrase: halfway
4. Prepositional Phrase: for the weekend
   • Preposition: for
   • Noun Phrase: the weekend
5. Prepositional Phrase: at a Walmart
   • Preposition: at
   • Noun Phrase: a Walmart

This structure can be visually represented in a diagram format, showcasing the relationships between the components of the sentence.