It is difficult to find a solvent for graphite among the common ones. However, it is possible to obtain a dispersion system, e.g., by centrifuging graphite in chlorosulfonic acid. Please see the link below.
Those interested at this query may possibly want to check also this RG discussion on reactive dissolution (with oxidation) of graphite: https://www.researchgate.net/post/Chemical_etchant_or_thermal_etching_condition_for_graphite