Install CMake:
https://cmake.org/download/

Open Run x64 Native Tools Command Prompt for VS 2019

Run the following commands (in a separate folder):

git clone https://github.com/mysql/mysql-server.git
cd mysql-server
git checkout mysql-5.7.38

cmake -G "Visual Studio 16 2019" -DDOWNLOAD_BOOST=1 -DWITH_BOOST=C:\dev\ext\boost .

cmake --build . --config Release