Lojban (j/k)
Looks like this problems has been solved quite a few times. Here are some options:
https://en.wikipedia.org/wiki/International_Phonetic_Alphabet
https://en.wikipedia.org/wiki/SaypYu
https://omniglot.com/conscripts/phonetic.htm (tons of options here)
The great thing about standards is that there are so many to choose from!