The viscosity and self-diffusion coefficients of C-60 in the gas phase are reported, based upon a first-principles interaction potential. It is found that these transport coefficients increase monotonically with increasing temperature, but the calculated collision integrals, which are closely related to the transport coefficients, do not decrease monotonically with increasing temperature and exhibit a number of plateaus or the oscillating behavior. It is completely different from those of inert gases. This phenomenon should be ascribed to the interaction potential between C-60 molecules. We confirm that the potential employed here does not behave like a Lennard-Jones (LJ) potential or Tang-Toennies (TT) potential and in turn a LJ-type or TT-type potential cannot describe exactly the interaction between C-60 molecules.