Dielectric properties of cyanoadamantane in the plastic phase are studied using a stochastic model for orientational relaxation. The jump rate distribution is assumed to be a power law function, and the master equation is solved within the coherent medium approximation. The orientational relaxation function is shown to be fitted well by a stretched exponential function. The exponent of the power law distribution function is related to temperature by comparing the Cole-Cole plot of the complex dielectric constant with experiments. The glass transition temperature is shown to correspond to the Vogel-Fulcher temperature where the relaxation time diverges.