Having not had to muck about with the X configuration in quite a while I've recently found that many Linux current distros no longer use an xorg.conf file (unless it is manually created for whatever reason) instead configuring X on the fly at boot. So where is this configuration stored now such that it can be perused? Somewhere in memory, I imagine.
X configuration location on systems that configure X on the fly at startup
xorg;configuration
Xorg logs to /var/log/Xorg.n.log where n is the server log file for display n. In newer implementations1, the log file may be found at $HOME/.local/share/xorg/Xorg.n.log.The log will contain all of the currently loaded values for the running display, including any configuration options loaded through conf files in /etc/X11/xorg.conf.d/.1. From Xorg 1.16, X can be run rootless via systemd-logind.