What is meant by "al-saw'ah" in the story of our master Adam, and does it refer to the sexual organs? And what was his body like before the sin?

The "Su'a" (private parts) that became apparent to Adam and Eve — peace be upon them — when they ate from the tree refers to the well-known major 'awrah (intimate parts), and it was named thus because its exposure distresses its owner. They were covered before eating from the tree, but when they ate from it, the covering was removed, and their private parts became visible. So, they began to cover them with leaves from the trees of Paradise.