Aperiodic perforated graphene layers were synthesized and used in fabrication of optical nanocavity absorbers. Chemical vapor deposition-grown graphene (Gr) layers were exposed to oxygen plasma etching to obtain the perforated graphene (pGr). The fabricated pGr/SiO2 (68 nm)/Ag (150 nm) nanocavity could present significant higher optical absorption, especially at around 530 nm wavelength region, as compared to a benchmark Gr/SiO2 (68 nm)/Ag (150 nm) sample. The effect of pore size of the pGr layer on the absorption property of the nanocavity has been studied by both experimental and numerical methods. The dependence of the absorption property of the nanocavity on the incident angles of unpolarized light and also the electrical/magnetical portion of transverse polarized light have been examined. The electrical interaction between the nanopores of the pGr and the incident light was found as the main reason for the absorption. The proposed graphene-based nanocavity resonator can further excite designing high efficient electromagnetic wave absorbers highly demanding two-dimensional coatings with effective optical absorption features.