In Lurie's Higher Topos Theory Proposition A.3.2.4, the author used Proposition A.2.6.15 to prove that for any combinatorial monoidal model category $\mathbf{S}$ with all objects cofibrant and weak equivalences stable under filtered colimits, the category $\mathbf{Cat_S}$ is a left proper combinatorial model ctegory, where he implicitly used the statement:

$\mathbf{Cat_S}$ is locally presentable.

Why is this statement true? Can anybody give me some help? Thanks in advance!