Where can I find the 'of the Wild' set?

According to this article, you will find the set in the Forgotten Temple.

All pieces of the armor set can be found in The Forgotten Temple.

From the page about the quest which rewards this armor set:

The reward which is an “of the Wild” armor set lies waiting at the foot of the Goddess Statue placed behind the local shrine.

For directions to the Forgotten Temple, here's where the wikia says it is:

It is a large building found at the northernmost end of Tanagar Canyon.

You can find the 'of the Wild' set in the Forgotten Temple behind the Rona Kachta Shrine in the Tabantha Region.

Location on interactive map.

Since you have already completed all the shrines you can just warp directly to Rona Kachta shrine and pick up your goodies. I wouldn't recommend traveling there on foot as there are a large number of guardians protecting the way.