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