Welcome to the community
Try to provide the color argument inside aes call. Compare the two graphs generated by p and q below:
library(ggplot2)
p <- ggplot(data = mpg,
mapping = aes(x = displ,
y = hwy),
colour = trans)
p +
geom_point() +
facet_wrap(facets = ~ class,
nrow = 2) +
labs(title = "p with colour outside aes")

q <- ggplot(data = mpg,
mapping = aes(x = displ,
y = hwy,
colour = trans))
q +
geom_point() +
facet_wrap(facets = ~ class,
nrow = 2) +
labs(title = "q with colour inside aes")

Hope this helps.
By the way, can you try without group = 1. Why are you using it?
I can't really test, because I don't have this data, and don't want to download the package just for this.
Can you please share a small part of the data set in a copy-paste friendly format?
In case you don't know how to do it, there are many options, which include:
-
If you have stored the data set in some R object, dput function is very handy.
-
In case the data set is in a spreadsheet, check out the datapasta package. Take a look at this link.