Download the latest CMake Mac binary distribution here: https://cmake.org/download/ (current latest is: https://cmake.org/files/v3.17/cmake-3.17.1-Darwin-x86_64.dmg)
Double click the downloaded .dmg file to install it. In the window that pops up, drag the CMake icon into the Application folder.
Add this line to your .bashrc file: PATH="/Applications/CMake.app/Contents/bin":"$PATH"
Reload your .bashrc file: source ~/.bashrc
Verify the latest cmake version is installed: cmake --version
You can launch the CMake GUI by clicking on LaunchPad and typing cmake. Click on the CMake icon that appears.