I have a custom made ansible role that does what you are asking for. I've wanted to clean it up a bit before putting it up on Github, and your post just gave me a motivation to stop procrastinating it :) This was initially made for my own use, and I'm not an Ansible expert so it can have some rough edges, but I tried my best to make it adhere to the Ansible way of doing things (applying the same role to a host twice should be idempotent).
Using this role, I'm able to quickly define wireguard networks, define which peer participates in which network, optionally configure a peer as a router (with NAT and port forwarding) for a given network. For Ansible-managed hosts, it installs wireguard, generates and deploys wireguard configurations, and enables IP forwarding on exit nodes. It can also generate ready-to-deploy wireguard configurations for externally managed hosts.
The repo is at https://github.com/pcouy/ansible-wireguard . I tried giving some instructions in the readme but they may not be detailed enough. If you try it, please open an issue for anything that's not clear enough from the readme so I can improve it. (I tried making a "Quick start" section for people who never used ansible before)