One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,5)(6,8)(9,10,14,19,15,18,13,29)(11,20,22,32,23,16,30,33)(12,24,28,34,26,39,27,17)(21,36,37,35,25,38,40,31)(2,5)(6,7)(9,11)(10,16)(12,25)(13,22)(14,30)(15,23)(17,31)(18,20)(19,32)(21,26)(24,38)(27,40)(28,37)(29,33)(34,35)(36,39) involution — undirected(9,12)(10,17,18,34)(11,21,23,25)(13,27)(14,28)(15,26)(16,31)(19,24,29,39)(20,35)(22,37,30,40)(32,38)(33,36)(1,3,4,8)(2,6,5,7)(10,18)(13,14)(16,20)(17,34)(22,30)(27,28)(31,35)(37,40)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.