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