The standard grips this chord is usually shown with.
Gsus2sus4 is G, A, C and D, a suspended second and fourth. The shape this page opens on is written 300213, lowest string first.

Also written Gsus2/4 or G suspended 2nd and 4th. The same chord either way; which spelling you meet depends on who wrote the chart.
There are 7 common shapes for Gsus2sus4 on the guitar, and 28 derived voicings in 3 families.
In which keys. Every note of Gsus2sus4 belongs to C major (the V), D minor (the iv), E minor (the ♭III), F major (the ii), G major (the I), G minor (the i), A minor (the ♭VII) and Bb major (the vi).
The common shapes, written lowest string first: 300213, 33021x, 33023x, 335535, x-10-7-7-8-8, x-10-10-12-10-10, 15-15-12-14-x-x.
Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. Gsus2sus4 has xx0213, x0001x, 3302xx, xx5535, 5555xx, xx7788, x-x-10-12-10-10, 10-12-10-12-x-x.
Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. Gsus2sus4 has 3x021x, x3x233, 5x553x, x5x585, 8x778x, x-10-x-7-10-8, x-12-x-12-13-10, 10-x-10-12-10-x.
Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. Gsus2sus4 has 5300xx, 3300xx, x0053x.
The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.