Recently, I have been self-teaching graph theory and having an organic chemistry course at school.

When I was learning isomer enumeration I found great resemblance between organic molecules and graphs. Every atom can be regarded as a vertex, with carbon vertices of $4$ degree, hydrogen atoms of $1$ degree etc. On the whole they just constitute a loopless yet usually not simple graph!

While I am excited about this idea, I am unclear about how to apply graph theory (and some combinatorial techniques) to chemistry.

Am I correct? Are there really applications of combinatorics or graph theory to organic chemistry, particularly isomer enumeration? If so how? Are there any books or resources from where I can learn about this amazing idea?