Generating triples of involutions of groups of Lie type of rank two over finite fields

For finite simple groups $U_5(2^n)$, $n>1$, $U_4(q)$, and $S_4(q)$, where $q$ is a power of a prime $p > 2$, $q-1\ne0\pmod4$, and $q\ne 3$, we explicitly specify generating triples of involutions two of which commute. As a corollary, it is inferred that for the given simple groups, the minimum number of generating conjugate involutions, whose product equals $1$, is equal to $5$.