You can divide the poem into sections by the visual elements the poet is describing. You can tell that the poet is explaining what he sees on this ancient piece of art by his question and answer technique and by his use of apostrophe to address is, as if it would answer his questions itself.
Each stanza describes a scene such as the "leaf fringed' border and the gods and maidens frolicing in a "mad pursuit" of one another in the first stanza.
In the second stanza, a lover playing a pipe is described as he wanes for his true love. In the third the speaker describes a religious ceremony with a priest and a "green altar".
Several other images present themselves to the viewer, and they all culminate in the final message:
"Beauty is truth, truth beauty," - that is all
Ye know on earth, and all ye need to know."
Here the poet is commenting upon the ultimate concept of beauty and how it can accurately reflect all humanity from all times.
Some of this information and a copy of the txt can be fourd at the link referenced below.