Of course there were moments where Gai made contact with Rikudou Madara's body while punching and kicking, but there is no proof that Gai landed blows on Madara instead of Madara blocking all of them while moving backwards to increase distance between themselves due to being overhelmed by Gai's taijutsu and being only able to react in time and block but no time for counter or to escape.
Exactly in my eyes it looks like Gai was attacking Madara while charging at him then Madara was blocking all of them while retreating/moving backwards because he was unable to counter attack Taijutsu assault made by Gai. Madara was unable to stop Gai but still was able to react in time to block, he was retreating/moving backwards because he felt unrelaxed and very uneasy so he wanted to create distance between himself and Gai but from picture you can easily conclude that Madara was in control over this situation, then he only got "?!" mark when Gai formed his hands in hirodura's typical handseal but Madara intercepted this attack splitting it in two halves.
so no, Madara was not overhelmed by speed of Gai.
Conclusion: Madara was overhelmed by Gai's taijutsu complex combat style, not his speed.