G5 guitar chord is also written as G5 or G(no 3).
Guitar chords chart for G5 chord with suggested finger positions on the guitar fretboard is shown below.
View 5 chord for guitar with other root notes
C - D - E - F - G - A - B - C♯ - D♯ - F♯ - G♯ - A♯ - D♭ - E♭ - G♭ - A♭ - B♭