The shader cache is stored in the following folder by default:
(You can paste this into File Explorer's address bar to go directly there.) ryujinx precompiled shaders
Here is the information regarding Ryujinx precompiled shaders in plain text. The shader cache is stored in the following
%appdata%\Ryujinx\bis\user\save\00000000\00000001\ ryujinx precompiled shaders
Shaders are programs that tell your GPU how to render graphics. In emulation, shaders must be translated from the Switch's format to your PC's GPU format. Precompiled shaders are pre-translated shaders saved to your disk. This allows the emulator to load them instantly instead of compiling them on the fly, which prevents stuttering during gameplay.
Inside this folder, you will see files with the extension .cache or .shader.cache . These are your precompiled shaders.