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