I was reading a PhD thesis and was pleasantly surprised to learn about the Lexicon Iconographicum Mythologiae Classicae (“Iconographic Lexicon of Classical Mythology”; a.k.a. LIMC; 1981-2009). It’s a 16-volume encyclopedia of ancient Greek, Roman, and Etruscan art showing historical examples for each deity. The books cover gods alphabetically, starting with “Atherion-Eros” and ending with “Thespiades-Zodiacus.”
The tomes appear to be presented in a series of matched volumes, the first comprising articles describing the art and the second with pictures.
Black and White PDFs of the full series are available on Internet Archive. See below for a screenshot of a couple of pages (of many) focusing on Heracles.
I would LOVE to get physical copies, but they are very expensive. Thankfully, there is a digital version.
https://app.dasch.swiss/project/BRwvcfLLT72IN-fXzQkrdQ/data
Hercules Omnibus 