documentclass[border=5mm]{standalone}
usepackage{tikz}

tikzset{
    3D/.style={
        x={(-3.85mm, -3.85mm)},
        y={(1cm, 0cm)},
        z={(0cm, 1cm)},
    },
}


begin{document}
begin{tikzpicture}[3D, scale=3]
    tikzset{>=stealth, shorten >=1pt}
    coordinate (sw) at (+1, -1, 0);
    coordinate (nw) at (-1, -1, 0);
    coordinate (ne) at (-1, +1, 0);
    coordinate (se) at (+1, +1, 0);
    coordinate (c)  at (0, 0, 0);

    draw (sw) -- (nw) -- (ne) node[right] {$S_{alpha(t)}$} -- (se) -- cycle;
    draw[->] (c) -- ++(0, 0, .7) node[above left] {$N(alpha(t))$};
    draw[->] (c) -- ++(-.3, .3, 0) node[below right] {$X'(t)$};
    draw[->] (c) -- ++(-.3, .3, .7) node[above right] {$dot X(t)$};
    draw[dashed] (c) ++(-.3, .3, 0) -- ++(0, 0, .7);
end{tikzpicture}
end{document}