Victory gave England their first 5-0 series sweep of Australia.
Bayliss will look to guide England to their first 5-0 ODI sweep of his native Australia when an ongoing series concludes at Old Trafford on Sunday.
Roy has bounced back in style from the disappointment of being dropped for the team's Champions Trophy semi-final defeat by eventual tournament winners Pakistan in Cardiff last year.
The concept of two new white balls in ODIs has ended reverse swing as an art in that format of cricket.
England finished on 314 for four, with Jos Buttler 54 not out, as they won with 32 balls to spare.
Australia coach Justin Langer termed Trent Bridge thrashing a 'shock' and hopes his side will learn from it.
Eoin Morgan's men took an unassailable 3-0 lead in Nottingham on Tuesday when they posted a new world record total at this level of 481 for six.
Nine top-ranked sides will participate in the inaugural edition of the World Test Championship, which will run from July 15, 2019 to April 30, 2021.
Australia have now suffered back-to-back ODI series defeats against England for the first time in 41 years.
Victory gave 2019 World Cup hosts England an unbeatable 3-0 lead.
Alex Hales top scored for England with 147 runs off just 92 balls.
Ben Stokes is expected to be available for the T20I series against India.
The wicket-keeper found himself unexpectedly thrust into the role when regular one-day international skipper Eoin Morgan pulled out shortly before the start of Saturday's second one-day international in Cardiff.
Jason Roy returned to the scene of one of his greatest disappointments to score a century as England beat Australia by 38 runs to win the second one-day international at Cardiff on Saturday.
The CPL announced on Saturday that the swashbuckling opener would replace his compatriot D'Arcy Short in the St Lucia side for their T20 event which runs from August 8 until September 16.
Justin Langer said he 'nearly died' when he heard of the ball-tampering scandal.
It was England's spinners who laid the platform for a much-needed victory following a stunning six-run defeat by non-Test nation Scotland in Edinburgh on Sunday.
Jonny Bairstow has insisted England can cope with the pressure of being the world's top-ranked one-day international side as they head into a five-match series against Australia on the back of a shock six-run defeat by Scotland.