Cosmic Dobie

So.....I have a question.....I use a Casio Privia PX-100 which I hook to the PA mixer for live gigs....when we had a snake I used to run it into a DI box and then an xlr mic cord to run it long distances. I recently bought a Behringer XR18 so the keyboard is now 20 feet from the mixer.....with the output on the Casio being limited to 1/8 stereo headphone jacks what is the best way to hook this up to the PA. For the last gig I used a Hosa cord with 1/8 TRS on one end and 1/4 TS on the other end, and hooked it into the mixer....I wasn't to impressed though....just looking for the best way to do this.....????....