It's depends on the experience of the Yasuo.
If he goes against squishy he can just build Shiv (E is enough to dodge skill shot, Q clear wave and shield win trade).
But if he goes against bruisers like Diana and still build Shiv path he will lose trade early. A smart Yasuo usually builds lifesteal (2 Doran + VampScepter) at least before SS. In some cases he even finish BoRK before SS. That will give Bruisers more trouble.
That's what usually I see from Yasuo vs Zed matchups. In Diana case, Windwall is useless against her WER and her AA. Even Q can bypass the windwall and the CDR is shorter.
On the other hand, if the jungler is squishy like Yi early coming to feed Diana, then Diana can win Yasuo even easier.