One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10,14,19,15,18,13,26)(11,16,21,32,22,30,27,31)(12,23,25,17,24,34,28,33)(20,35,38,40,36,39,37,29)(2,6)(3,4)(7,8)(9,11,14,21,15,22,13,27)(10,16,19,32,18,30,26,31)(12,20,25,38,24,36,28,37)(17,29,34,35,33,40,23,39)(9,12)(10,17)(11,20)(13,28)(14,25)(15,24)(16,29)(18,33)(19,34)(21,38)(22,36)(23,26)(27,37)(30,40)(31,39)(32,35) involution — undirected(1,3,5,4)(2,7,8,6)(10,18)(16,30)(17,33)(19,26)(23,34)(29,40)(31,32)(35,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.