Diawara had been suspended from Senegal's next two Group E qualifiers after the referee reported cautioning him in their last match, a tempestuous goalless draw in Cameroon in June during which two Senegal players were sent off and their coach Amara Traore was sent to the stands.
CAF said it had examined video evidence and found Diawara had not been booked as the Angola referee Helder Martins de Carvalho had reported.
The Cairo-based footballing body said it had been a case of mistaken identity as Diawara had been confused with midfielder Issiar Dia, who has already been suspended for two matches after receiving a red card in the game.
The referee's performance was denounced by Senegal prime minister Souleymane Ndene Ndiaye, who at the time blamed controversy-plagued CAF president Issa Hayatou, who is from Cameron.
"Issa Hayatou no longer has the merit to lead CAF. He sat and watched with his eyes in his homeland a refereeing scandal, which brings no pride to African football," Ndiaye said.
Diawara is now available for the return match against Cameroon in Dakar in September. A home win would allow Senegal to qualify for next year's Nations Cup finals, eliminating Cameroon, who played at last year's World Cup finals.
