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