sns.set_style("whitegrid")

ax = sns.scatterplot(x=x, y=y, s=125)

ax.set_xlim(-20, 20)
ax.set_ylim(-20, 20)

ax.spines['left'].set_position('zero')
ax.spines['left'].set_color('black')

ax.spines['right'].set_color('none')
ax.yaxis.tick_left()

ax.spines['bottom'].set_position('zero')
ax.spines['bottom'].set_color('black')

ax.spines['top'].set_color('none')
ax.xaxis.tick_bottom()

values = ax.get_xticks()
ax.set_xticklabels(["{0:.0%}".format(x/100) for x in values])

values = ax.get_yticks()
ax.set_yticklabels(["{0:.0%}".format(y/100) for y in values])

ax.tick_params(axis='both', which='major', labelsize=15)

ax.grid(True)