Or if you don’t want to wait as recommended, there;s always the AUR, which seems to have it:
$ pamac search --aur nvidia
[...]
nvidia-beta-dkms 550.40.07-1 AUR
NVIDIA driver sources for linux (beta version)
[...]
So that’s an option:
pamac build nvidia-beta-dkms
Note:
This is the AUR, so not really recommended, nor supported. Just like @MrLavender mentioned about building, installing and maintaining it manually. So, while use of the AUR is possible, it’s neither recommended nor supported.
Lastly, all disclaimers and suggestion regarding AUR usage applies: