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