Well, your sample data is not suitable for a scatter plot but I have no problem making one, maybe you are just making a typo, have in mind that R is case sensitive and "sex" is not the same as "Sex".
df <- data.frame(drating = c(0, -2, -2, 18.2125, 3.587, 0, -2, 0, 0, 0, -2, -2, 1.7155,
0.116, -2, -2, 0.058, 4.5, 0.808, 0.145),
Sex = as.factor(c("Female", "Male", "Female", "Male", "Female",
"Female", "Female", "Male", "Female", "Male",
"Male", "Female", "Male", "Female", "Female", "Male",
"Female", "Male", "Male", "Female"))
)
library(ggplot2)
ggplot(df, aes(x = Sex, y = drating, colour = Sex)) +
geom_point()

Created on 2019-04-08 by the reprex package (v0.2.1.9000)