Hello,
For better results in Google PageSpeed please kindly follow the link below:
http://www.wpmayor.com/how-to-achieve-google-pagespeed-score-90-higher/
Also you can use some additional plugins for compression, caching (W3 Total Cache etc), image optimization (WP Smush etc.) and Javascript / CSS Minifiers.
To improve page speed we would recommend to use cache plugin. For example W3 Total cache, because it has almost all the necessary options. Please read this article how to set up W3 Total Cache plugin:
http://zemalf.com/1443/w3-total-cache/
You can speed up the site following the suggestions from these articles:
http://techtage.com/speeding-up-wordpress-sites/
http://www.sparringmind.com/speed-up-wordpress/
https://www.inmotionhosting.com/support/website/wordpress/heartbeat-ajax-php-usage#heartbeat-in-action
http://premium.wpmudev.org/blog/10-best-image-optimization-plugins-to-speed-up-your-wordpress-site/
http://www.elegantthemes.com/blog/tips-tricks/optimize-images-for-your-wordpress-website
Regards,
Rose Tyler.