The standard grips this chord is usually shown with.
Csus2sus4 is C, D, F and G, a suspended second and fourth. The shape this page opens on is written x33033, lowest string first.

Also written Csus2/4 or C suspended 2nd and 4th. The same chord either way; which spelling you meet depends on who wrote the chart.
There are 6 common shapes for Csus2sus4 on the guitar, and 27 derived voicings in 3 families.
In which keys. Every note of Csus2sus4 belongs to C major (the I), C minor (the i), D minor (the ♭VII), Eb major (the vi), F major (the V), G minor (the iv), A minor (the ♭III) and Bb major (the ii).
The common shapes, written lowest string first: x33033, x30011, x33533, 8857xx, 8-8-10-10-8-10, x-15-12-12-13-13.
Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. Csus2sus4 has 1300xx, xx0011, xx3533, 3535xx, x3303x, x5556x, x-x-10-10-8-10, 10-10-10-10-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. Csus2sus4 has 1x001x, x3x031, x5x563, 3x353x, 8x576x, x8x788, 10-x-10-10-8-x, x-10-x-10-13-10.
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. Csus2sus4 has xx0063, 3x006x.
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.