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