How do you diagram this sentence:

Government by the people is foundation of democracy.

I can't do the visual here. How about if I give you parts of speech?

Government = subject
by the people = prepositional phrase (do you know how to diagram that off the subject?)

is = verb

foundation = predicate nominative, i.e. predicate noun
of democracy = prepositional phrase off "foundation"

____________|______\___________
\______
... \

Check this for the visuals of diagramming --

Diagramming Sentences Index (http://www.english-grammar-revolution.com/diagramming-sentences.html)