Babai, Kantor and Lubbotsky proved the following theorem.
THEOREM 1.1. There is a constant $C$ such that every nonabelian finite simple group $G$ has a set $S$ of at most 7 generators for which the diameter of $Cay(G,S)$ is at most $C\log|G|$.
Then they remark that
"A crude estimate for $C$ is $10^{10}$, but we will not include the bookkeeping required to estimate $C$."
This is my question.
"Is there a finite simple group $G$ for which there exists a generating which satisfies the conditions in the above theorem for some reasonably small $C$ (comparing to the order of $G$)?"