One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,12)(9,10)(13,14)(15,20)(16,18)(17,19)(23,28)(25,27) involution — undirected(2,4)(6,10)(8,11)(13,15,17,16)(14,18,19,20)(21,22,26,24)(23,27,28,25)(1,2)(3,4)(6,10)(7,12)(15,16)(18,20)(21,23,26,28)(22,27,24,25)(5,7)(6,8)(9,12)(10,11)(13,16,17,15)(14,18,19,20)(21,24,26,22)(23,25,28,27)(5,8)(6,7)(9,11)(10,12)(13,14)(15,20)(16,18)(17,19)(21,25)(22,23)(24,28)(26,27) involution — undirectedA 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.