Every fingering that fits a hand
6644
moderate
664x
easy
6899
hard
What is true of it
D♭sus4 is D♭, G♭ and A♭ — 1, 4 and 5 counted from D♭.
These are also the notes of G♭sus2/D♭ and F♯sus2/D♭. Which name is right depends on what is underneath and what came before — the notes alone do not decide.
The easiest of the 3 fingerings below is 6644: 4 fingers, held at the 4th fret.
None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.
Where its notes are on the neck
The brass dots are D♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
D♭sus4/G♭
x644
D♭sus4/A♭
112x
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.