Born in Guinea, he is a member of the Spain national team.

[2] When he was six years old he attended a talent scouting program at his school in Manresa and was encouraged to start gymnastics by the coaches who saw his potential.

[2][3] Diallo was naturalized in 2015 and debuted with the senior national gymnastics team in 2018.

[2] Diallo won a team all-around gold medal at the 2018 Mediterranean Games along with Néstor Abad, Nicolau Mir, Alberto Tallón and Rayderley Zapata.

[2] At the Spanish national championships, Diallo placed third in 2018 and second in 2020 in the individual all-around.