I am trying to make a latex table that looks like the picture. There should basically be 4 columns of rotated text under Header 1, one grey cell that that contains additional information. I am new to latex and have no idea how to make this table in booktabs style. 
\documentclass{article}
\newcommand*\turn{\rotatebox[origin=b]{90}}
\usepackage{array}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{array, caption}
\usepackage{graphicx}
\usepackage{makecell}
\usepackage[table,xcdraw]{xcolor}
\begin{document}
\begin{table}[]
\centering
\begin{tabular}{@{}llllll@{}}
\toprule
& \multicolumn{4}{c}{Header 1} & \
\cmidrule(lr){2-5}
&\turn{Text1} &\turn{Text2} &\turn{Text3} & \turn{Text4} & \cellcolor{gray!25} \makecell[l]{Some line 1\ Some line 1\ Some line 1\ Some line 1\ Some line 1} \
Header 3 & & & & &Header 3\
\midrule
& & & & & \
& & & & & \
\bottomrule
\end{tabular}
\end{table}
\end{document}



