Use the Embed URL function on the Insert menu and enter your Group's URL

Here's a video from 'Steegle' showing you how to Embed Google Groups in New Google Sites.

Instead of embedding I suggest that you provide a link to the group:

For this Group:

  • Anyone can view content.

  • Anyone can join.

  • Anyone can post.

  • All posts are held for moderation.

  • Only members can view the list of members