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