A marching on-in-time (MOT) scheme for analyzing transient electromagnetic wave interactions on graphene sheets is described. The proposed scheme discretizes a time domain-resistive boundary condition (TDRBC) enforced on the infinitesimally thin graphene sheet. Time domain samples of the graphene's surface resistivity required by the MOT-TDRBC solver are computed from its frequency domain samples using a fast relaxed vector fitting (FRVF) algorithm. Numerical results, which demonstrate the applicability and accuracy of the proposed scheme, are presented.