Chebyshev poles into transfer function
The transfer function is

$$H(s)=\frac{g}{\prod_k(s-p_k)}\tag{1}$$

where $g$ is a scaling constant which is usually chosen such that the maximum value of the magnitude of $H(j\omega)$ equals $1$.

For a third order (or any odd-order) Chebyshev filter, a maximum occurs at $\omega=0$, so the gain constant can be derived from the requirement $H(0)=1$:

$$g=\prod_k(-p_k)=-\prod_kp_k$$

For your example the gain constant is $g=0.49134$.