  We investigate the spin Hall effect in a single-layer graphene device with
disorder and interface-induced spin-orbit coupling. Our graphene device is
connected to four semi-infinite leads that are embedded in a
{Landauer-B\"uttiker} setup for quantum transport. We show that the spin Hall
angle of graphene devices exhibits mesoscopic fluctuations that are similar to
metal devices. Furthermore, the product between the {maximum spin Hall angle
deviation} and dimensionless longitudinal conductivity follows a universal
relationship $\Theta_{sH} \times \sigma = 0.18$. Finally, we compare the
universal relation with recent experimental data and numerically exact
real-space simulations from the tight-binding model.
