Addressing the ecological issues through sunlight-driven photocatalytic oxidation is a challenging and exciting theme. Therefore, different kinds of photo-active materials have been designed so far to tackle the problem of wastewater pollution. In this study, multilayered graphene with platelets morphology is integrated with CeO$_2$ nanoparticles (NPs) to design GNPs/CeO$_2$ (GNPs: CeO$_2$ = 1:3, 1:1 and 3:1) nanocomposites (NCs) using ultrasonic method. The physical properties of CeO$_2$ have been tuned by varying the loading content of GNPs. These NCs have been characterized for their physico-chemical properties, which confirmed the formation of the NCs with porous morphology, tuned bandgap and enhanced photocatalytic characteristics. The GNPs/CeO$_2$ NCs have displayed considerably enhanced capability to decompose methylene blue as compared to the pristine CeO$_2$ NPs. The improvement in photodegradation activity of the NC can be attributed to the tuned bandgap and effective transport of photoelectrons in the conducting channels providedby GNPs in the structure. GNPs/CeO$_2$ NCs can be auspicious photocatalyst for industrial wastewater treatment.