documentclass[tikz,border=3.14mm]{standalone}
usetikzlibrary{arrows.meta,shapes.geometric}
newcounter{pft}
begin{document}
begin{tikzpicture}[font=sffamily,pics/cgram/.style={code={
foreach XX [count=YY starting from 0] in {1,...,#1}
{pgfmathsetmacro{mycolor}{{LstCols}[YY]}
node[circle,draw,minimum size=2.5em,fill=mycolor] (c-#1-XX) at
({{LstAngles}[#1-2]-YY*360/#1}:1.5) {setcounter{pft}{XX}Alph{pft}};}
foreach XX [evaluate=XX as Ymax using {int(XX-1)}] in {2,...,#1}
{foreach YY  in {1,...,Ymax}
{pgfmathsetmacro{mycolorA}{{LstCols}[XX-1]}
pgfmathsetmacro{mycolorB}{{LstCols}[YY-1]}
draw[{Stealth[fill=mycolorB,length=7pt]}-{Stealth[fill=mycolorA,length=7pt]}] (c-#1-XX) -- (c-#1-YY);}}
}}]
defLstCols{"red","orange","yellow","green!70!black","blue!70!white","purple!80!white"}
defLstAngles{180,150,135,128,120}
path (-5,0) pic {cgram=2} (0,0.5) pic {cgram=3} (5,0) pic {cgram=4}
 (-3,-4) pic {cgram=5}  (3,-4) pic {cgram=6};
end{tikzpicture}
end{document}