We determine the (non-Abelian) algebra of generalized symmetries for the SDiff(2)Toda equation, a pde for a single function of three independent variables, the solutions of which determine self-dual, vacuum solutions of the Einstein field equations. This algebra is a realization of two copies of the abstract algebra SDiff(2), along with an additional pair of elements that have derivation-like properties on both of the copies. It contains as a subalgebra the doubly-infinite, Abelian algebra, equivalent to the infinite hierarchy of higher flows found by Takasaki and Takebe. An infinite prolongation of the jet bundle for the original pde, to include all the variables allowed in their hierarchy, is required for the presentation of this generalization. Because these symmetries have non-zero commutators, they generate a recursion relation, allowing the generation and description of the entire algebra.