Play the cycle of 5th at the keyboard starting at C (12 o’clock)  and going clockwise up a a 5th to G (1 o’clock).  You could play the D (2 o’clock) above G as the next key, but stepping down a 4th to D keeps you within the same octave on the keyboard.  The sharp keys are presented in sequence of  a 5th step up alternating with a 4th step down. The flat keys are presented in sequence of a 5th step down alternating with a  4th step up.