It's often used as a humorous example of a long, complex, and seemingly unpronounceable word.
You could have fun with it and pronounce it however you like!
Here are a few ideas:
* "ee-loh-go-fus-ee-oh-hi-po-po-kun-yoo-ree-us" (breaking it down into its parts)
* "el-loh-go-foo-shee-oh-hip-po-kun-yoo-ree-us" (with a bit more flow)
* "ee-loh-go-fus-ee-oh-hip-po-kun-yoo-ree-us" (shortening some syllables)
Ultimately, it's up to you! Let your imagination run wild.