The G lydian dominant seventh chord is a 5-note chord consisting of the notes G, B, D, F and C#.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as G7#11.
Chords that are a subset of G7#11. These contain less notes but all of them are included in G7#11.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the G7#11 chord. Feel free to save or share the image as needed.