  Diquark excitations of dense quark matter are considered in the framework of
the Nambu -- Jona-Lasinio model with three types of massless quarks in the
presense of a quark number chemical potential $\mu$. We investigate the
effective action of meson- and diquark fields at sufficiently high values of
$\mu$, where the color--flavor locked (CFL) phase is realized, and prove the
existence of NG-bosons in the sector of pseudoscalar diquarks. In the sector of
scalar diquarks an additional NG-boson is found, corresponding to the
spontaneous breaking of the U(1)$_B$ baryon symmetry in the CFL phase. Finally,
the existence of massive scalar and pseudoscalar diquark excitations is
demonstrated.
