Actea savignii has an oval carapace which is slightly convex on the dorsal surface with a flat median region and a width which is about 1.3 times its length; the dorsal regions of the carapace have a covering of large, smooth, rounded, petal-shaped, dense tubercles.

The anterolateral margin is slightly curved and is divided into four vaguely defined, tuberculate, rounded lobes while the anteriormost is barely marked.

The front margin is strongly curved, and is equivalent to about 0.35 times the width of the carapace, it has two lobes along the sinuous frontal margin; the two lobes being divided by a wide V-shaped cleft.

The walking legs are also densely covered on tubercules, with larger conical tubercles on the upper surface of the carpus and propodus.

The dorsal surface of the carapace is yellowish with obvious purple-brown blotches on the orbital and cardiac regions.