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